Evaluation of root dentin defect formation during retreatment procedure using various NiTi rotary retreatment files: an in vitro study

Kurşun H., Gökyay S. S., Yalçın T. Y., Dinçol M. E.

Journal of scientific reports-A (Online), sa.064, ss.78-89, 2026 (TRDizin)

Özet

The focus of the present study was to evaluate the incidence of dentinal microcracks following use of three distinct NiTi-based retreatment systems on extracted human teeth. 125 extracted human mandibular premolars with single canals and roots were selected for the study. The remaining 100 teeth were prepared using the ProTaper Next NiTi rotary system up to the X3 file (30/.07), while 25 specimens were left unprepared as controls. Gutta-percha cones and TotalFill BC sealer were used in a single-cone procedure to obturate the canals. There was no retreatment after 25 teeth were filled. Three experimental groups (n=25) were randomly selected 75 specimens based on retreatment system: ProTaper Universal Retreatment, R-Endo and XP-endo Rise Retreatment. In order to detect and score any dentinal crack formation, the roots were carefully examined under a stereomicroscope at 20× magnification after completing retreatment procedures. NCSS was used for statistical analysis. Chi-square and McNemar tests were used for calculating descriptive statistics. A p-value <0.05 was considered significant. No significant differences were observed among retreatment systems and control groups at any root level regarding dentinal defect scores or presence (p > 0.05). The majority of specimens showed no defects, and higher defect scores were infrequently observed. The negative control showed intact dentin throughout, and the positive control demonstrated minimal defects. Neither inter- nor intragroup comparisons revealed significant differences, and none of the instruments significantly increased dentinal defect incidence; however, the XP-endo Rise system showed a nonsignificant tendency toward fewer defects.